XML is rapidly becoming the vehicle of choice as a definition language for the description of content-related structures. XML provides great flexibility and universality because XML provides a grammar that can express nearly any content. On the Internet in particular, the standardized representation of content structures generates unexpected opportunities.
More and more, mission-critical applications are designed to run on the Internet. Add the logical structuring capability of XML to the mix, and a new infrastructure that is ideal for running electronic business applications on the Internet becomes much more feasible. Databases can now be accessed directly via XML without having to use CGI and HTML or Java in addition.
Relational databases provide a primary tool for businesses to maintain, access, and analyze data. Such database technologies have evolved over many years so that they are optimized for accessing and manipulating large information bases. Many businesses store the majority of their critical information in 5 relational databases. Moreover, many Internet sites managed their data using relational database technology. This approach also makes it possible to develop database search engines for sifting through the large volumes of information that “live” on the Internet.
The combination of database technology with a self-describing structure of hierarchical languages such as XML opens an interesting perspective for new applications.
The implementation of the kind of tree structures supported by hierarchical languages such as XML in the form of a relational data model presents a number of issues, some of which have already been addressed and 15 solved. One vexing issue is presented when transmitting large amounts of data over the Internet in the form of hierarchical data such as XML. A mechanism that permits large databases to exchange data in the form of hierarchical data structures is desirable.